Updated http_cache/* articles to Symfony 4

Author: javiereguiluz

http_cache.rst

@@ -81,18 +81,15 @@ Enabling the proxy is easy: each application comes with a caching kernel (``AppC
 that wraps the default one (``AppKernel``). The caching Kernel *is* the reverse
 proxy.
 
-To enable caching, modify the code of your front controller. You can also make these
-changes to ``index.php`` to add caching to the ``dev`` environment::
+To enable caching, modify the code of your ``index.php`` front controller::
 
     // public/index.php
     use Symfony\Component\HttpFoundation\Request;
 
     // ...
-    $kernel = new AppKernel('prod', false);
-    $kernel->loadClassCache();
+    $kernel = new Kernel($_SERVER['APP_ENV'] ?? 'dev', $_SERVER['APP_DEBUG'] ?? false);
 
-    // add (or uncomment) this new line!
-    // wrap the default Kernel with the AppCache one
+    // add (or uncomment) this line to wrap the default Kernel with the AppCache one
     $kernel = new AppCache($kernel);
 
     $request = Request::createFromGlobals();
@@ -120,7 +117,9 @@ finely tuned via a set of options you can set by overriding the
 :method:`Symfony\\Bundle\\FrameworkBundle\\HttpCache\\HttpCache::getOptions`
 method::
 
-    // app/AppCache.php
+    // src/AppCache.php
+    namespace App;
+
     use Symfony\Bundle\FrameworkBundle\HttpCache\HttpCache;
 
     class AppCache extends HttpCache
@@ -137,10 +136,9 @@ method::
 For a full list of the options and their meaning, see the
 :method:`HttpCache::__construct() documentation <Symfony\\Component\\HttpKernel\\HttpCache\\HttpCache::__construct>`.
 
-When you're in debug mode (either because your booting a ``debug`` kernel, like
-in ``index.php`` *or* you manually set the ``debug`` option to true), Symfony
-automatically adds an ``X-Symfony-Cache`` header to the response. Use this to get
-information about cache hits and misses.
+When you're in debug mode (the second argument of ``Kernel`` constructor in the
+front controller is ``true``), Symfony automatically adds an ``X-Symfony-Cache``
+header to the response. Use this to get information about cache hits and misses.
 
 .. _http-cache-symfony-versus-varnish:
 
@@ -150,7 +148,7 @@ information about cache hits and misses.
     website or when you deploy your website to a shared host where you cannot
     install anything beyond PHP code. But being written in PHP, it cannot
     be as fast as a proxy written in C.
-    
+
     Fortunately, since all reverse proxies are effectively the same, you should
     be able to switch to something more robust - like Varnish - without any problems.
     See :doc:`How to use Varnish </http_cache/varnish>`
@@ -192,7 +190,7 @@ These four headers are used to help cache your responses via *two* different mod
 
     All of the HTTP headers you'll read about are *not* invented by Symfony! They're
     part of an HTTP specification that's used by sites all over the web. To dig deeper
-    into HTTP Caching, check out the documents `RFC 7234 - Caching`_ and 
+    into HTTP Caching, check out the documents `RFC 7234 - Caching`_ and
     `RFC 7232 - Conditional Requests`_.
 
     As a web developer, you are strongly urged to read the specification. Its
@@ -214,7 +212,7 @@ The *easiest* way to cache a response is by caching it for a specific amount of
     use Symfony\Component\HttpFoundation\Response;
     // ...
 
-    public function indexAction()
+    public function index()
     {
         // somehow create a Response object, like by rendering a template
         $response = $this->render('blog/index.html.twig', []);

http_cache/cache_invalidation.rst

@@ -50,7 +50,7 @@ cache instead of going to the application to get a response.
 Here is how you can configure the Symfony reverse proxy to support the
 ``PURGE`` HTTP method::
 
-    // app/AppCache.php
+    // src/AppCache.php
 
     use Symfony\Bundle\FrameworkBundle\HttpCache\HttpCache;
     use Symfony\Component\HttpFoundation\Request;

http_cache/esi.rst

@@ -62,14 +62,14 @@ First, to use ESI, be sure to enable it in your application configuration:
 
     .. code-block:: yaml
 
-        # app/config/config.yml
+        # config/packages/framework.yaml
         framework:
             # ...
             esi: { enabled: true }
 
     .. code-block:: xml
 
-        <!-- app/config/config.xml -->
+        <!-- config/packages/framework.xml -->
         <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/symfony"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
@@ -87,7 +87,7 @@ First, to use ESI, be sure to enable it in your application configuration:
 
     .. code-block:: php
 
-        // app/config/config.php
+        // config/packages/framework.php
         $container->loadFromExtension('framework', array(
             // ...
             'esi' => array('enabled' => true),
@@ -104,7 +104,7 @@ independent of the rest of the page.
     // ...
     class DefaultController extends Controller
     {
-        public function aboutAction()
+        public function about()
         {
             $response = $this->render('static/about.html.twig');
             // set the shared max age - which also marks the response as public
@@ -195,7 +195,7 @@ of the master page.
     // ...
     class NewsController extends Controller
     {
-        public function latestAction($maxPerPage)
+        public function latest($maxPerPage)
         {
             // ...
             $response->setSharedMaxAge(60);
@@ -220,14 +220,14 @@ that must be enabled in your configuration:
 
     .. code-block:: yaml
 
-        # app/config/config.yml
+        # config/packages/framework.yaml
         framework:
             # ...
             fragments: { path: /_fragment }
 
     .. code-block:: xml
 
-        <!-- app/config/config.xml -->
+        <!-- config/packages/framework.xml -->
         <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
@@ -245,7 +245,7 @@ that must be enabled in your configuration:
 
     .. code-block:: php
 
-        // app/config/config.php
+        // config/packages/framework.php
         $container->loadFromExtension('framework', array(
             // ...
             'fragments' => array('path' => '/_fragment'),

http_cache/validation.rst

@@ -66,7 +66,7 @@ To see a simple implementation, generate the ETag as the md5 of the content::
 
     class DefaultController extends Controller
     {
-        public function homepageAction(Request $request)
+        public function homepage(Request $request)
         {
             $response = $this->render('static/homepage.html.twig');
             $response->setEtag(md5($response->getContent()));
@@ -131,7 +131,7 @@ header value::
 
     class ArticleController extends Controller
     {
-        public function showAction(Article $article, Request $request)
+        public function show(Article $article, Request $request)
         {
             $author = $article->getAuthor();
 
@@ -190,7 +190,7 @@ exposing a simple and efficient pattern::
 
     class ArticleController extends Controller
     {
-        public function showAction($articleSlug, Request $request)
+        public function show($articleSlug, Request $request)
         {
             // Get the minimum information to compute
             // the ETag or the Last-Modified value